Highest temperature in Shanghai on August 21?

Platform comparison

Market context

Shanghai's highest temperature on 21 August 2026 will be measured at Pudong International Airport Station and resolved against Weather Underground's Daily Observations table rather than summary figures. The market currently prices this contract at 0% across all temperature bands, suggesting traders perceive no meaningful probability mass in any single range—an unusual state for a weather contract that will certainly resolve to some recorded value. On Polygon, USDC holders can acquire conditional tokens representing specific temperature brackets, with settlement determined by the precise hourly reading captured in Weather Underground's primary data feed rather than derived day-high summaries.

August temperatures in Shanghai historically cluster between 32–35°C, with extreme heat occasionally pushing toward 37–38°C during particularly intense heatwaves. The 2013 summer saw Shanghai record 38.3°C, and more recently, July 2022 brought sustained temperatures above 35°C across multiple weeks. The current 0% pricing suggests either incomplete market formation or trader uncertainty about which temperature band will ultimately contain the day's peak—a rational stance given that August weather in Shanghai remains genuinely variable despite seasonal patterns.

Traders should monitor China Meteorological Administration forecasts released in mid-August 2026, which typically provide 10-day outlooks with reasonable accuracy. Typhoon activity in the Western Pacific during late summer can suppress temperatures significantly, whilst high-pressure systems over central China drive heat northward into the Yangtze River Delta. Any tropical cyclone tracking toward eastern China in the week preceding 21 August would materially shift probability distributions toward cooler bands.

Methodology

We track Highest temperature in Shanghai on August 21? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

UK Frequently Asked Questions

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Scam?. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.